This invention relates to a fluid dynamic pressure bearing device in which a shaft member is supported by a bearing member, using dynamic pressure of a lubricant, such that relative rotation between the shaft member and bearing member is possible. This invention may also relate to a spindle motor provided with the fluid dynamic pressure bearing device, and to a recording disk drive device provided with the fluid dynamic pressure bearing device. This invention relates particularly to improvement of a capillary seal portion that suppresses lubricant filled in the fluid dynamic pressure bearing device from leaking to the outside, using capillarity.
Recently, in recording disk drive devices such as a magnetic disk or an optical disk used for a computer, there is a strong demand for higher density in addition to miniaturization, thinness, and lightness. Because of this, there is a strong demand for increasing the rpm (revolutions per minute) and improving rotation precision of a spindle motor used for disk rotation. In order to meet such a demand, instead of using a conventional ball bearing as a bearing device for a spindle motor, a fluid dynamic pressure bearing device is used that rotatably supports a rotation shaft by a bearing member, using fluid dynamic pressure of a lubricant.